Development of aerial inspection monitor (AIM) systems is critical to the effort to develop semiconductor processing techniques in the extreme ultraviolet (EUV). These AIM systems are used for inspection of the masks for the EUV.
The challenge surrounds the fact that the EUV masks are phase shift masks. As a result, actinic imaging systems are required to find any defects. Magnification and detection of images from the masks are difficult in these short wavelengths where standard optics do not work.
Currently actinic systems for EUV mask inspect utilize reflective optical systems that are expensive and inefficient. Moreover, the optical trains associated with these systems are complex.